In Chapter 2, Châtelet starts from Oresme's famous latitudo formarum diagrams (above) as a kind of horizon-screen of intensities, showing how modern physics emerges from this projection of motion first into the viewable spectra, then leading to the rhythm-diagram of the pendulum, and eventually the twin "symmetrical fans" of relativity and quantum theory which "bend" space-time and momentum-space onto the screen.